lttng/org.eclipse.tracecompass.lttng2.kernel.core/src/org/eclipse/tracecompass/internal/lttng2/kernel/core/event/matching/TcpLttngEventMatching.java

   1 /*******************************************************************************
   2  * Copyright (c) 2013, 2016 École Polytechnique de Montréal
   3  *
   4  * All rights reserved. This program and the accompanying materials are made
   5  * available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Geneviève Bastien - Initial implementation and API
  11  *   Patrick Tasse - Remove getSubField
  12  *******************************************************************************/
  13
  14 package org.eclipse.tracecompass.internal.lttng2.kernel.core.event.matching;
  15
  16 import java.util.HashMap;
  17 import java.util.HashSet;
  18 import java.util.Map;
  19 import java.util.Set;
  20 import java.util.WeakHashMap;
  21
  22 import org.eclipse.tracecompass.analysis.os.linux.core.trace.IKernelAnalysisEventLayout;
  23 import org.eclipse.tracecompass.analysis.os.linux.core.trace.IKernelTrace;
  24 import org.eclipse.tracecompass.tmf.core.event.ITmfEvent;
  25 import org.eclipse.tracecompass.tmf.core.event.TmfEventField;
  26 import org.eclipse.tracecompass.tmf.core.event.matching.IEventMatchingKey;
  27 import org.eclipse.tracecompass.tmf.core.event.matching.ITmfMatchEventDefinition;
  28 import org.eclipse.tracecompass.tmf.core.event.matching.TcpEventKey;
  29 import org.eclipse.tracecompass.tmf.core.event.matching.TmfEventMatching.Direction;
  30 import org.eclipse.tracecompass.tmf.core.trace.ITmfTrace;
  31 import org.eclipse.tracecompass.tmf.core.trace.ITmfTraceWithPreDefinedEvents;
  32 import org.eclipse.tracecompass.tmf.core.trace.TmfEventTypeCollectionHelper;
  33
  34 /**
  35  * Class to match tcp events. They use the main kernel's tracepoints
  36  * netif_receive_skb and net_dev_queue to check if they have a TCP header and
  37  * use the sequence, acknowledge and flags fields to match packets
  38  *
  39  * @author Geneviève Bastien
  40  */
  41 public class TcpLttngEventMatching implements ITmfMatchEventDefinition {
  42
  43     private static final Map<IKernelAnalysisEventLayout, Set<String>> REQUIRED_EVENTS = new HashMap<>();
  44
  45     /** Use a weak hash map so that traces can be garbage collected */
  46     private static final Map<ITmfTrace, IKernelAnalysisEventLayout> TRACE_LAYOUTS = new WeakHashMap<>();
  47
  48     @Override
  49     public boolean canMatchTrace(ITmfTrace trace) {
  50         // Get the events that this trace needs to have
  51         if (!(trace instanceof IKernelTrace)) {
  52             // Not a kernel trace, we cannot know what events to use, return
  53             // false
  54             return false;
  55         }
  56         IKernelAnalysisEventLayout layout = ((IKernelTrace) trace).getKernelEventLayout();
  57         TRACE_LAYOUTS.put(trace, layout);
  58
  59         Set<String> events = REQUIRED_EVENTS.get(layout);
  60         if (events == null) {
  61             events = new HashSet<>();
  62             events.addAll(layout.eventsNetworkSend());
  63             events.addAll(layout.eventsNetworkReceive());
  64             REQUIRED_EVENTS.put(layout, events);
  65         }
  66
  67         if (!(trace instanceof ITmfTraceWithPreDefinedEvents)) {
  68             // No predefined events, suppose events are present
  69             return true;
  70         }
  71         ITmfTraceWithPreDefinedEvents ktrace = (ITmfTraceWithPreDefinedEvents) trace;
  72
  73         Set<String> traceEvents = TmfEventTypeCollectionHelper.getEventNames(ktrace.getContainedEventTypes());
  74         traceEvents.retainAll(events);
  75         return !traceEvents.isEmpty();
  76     }
  77
  78     /**
  79      * @since 1.0
  80      */
  81     @Override
  82     public Direction getDirection(ITmfEvent event) {
  83         IKernelAnalysisEventLayout layout = TRACE_LAYOUTS.get(event.getTrace());
  84         if (layout == null) {
  85             return null;
  86         }
  87         String evname = event.getName();
  88         /* Is the event a tcp socket in or out event */
  89         if (layout.eventsNetworkReceive().contains(evname)) {
  90             return Direction.EFFECT;
  91         } else if (layout.eventsNetworkSend().contains(evname)) {
  92             return Direction.CAUSE;
  93         }
  94         return null;
  95     }
  96
  97     @Override
  98     public IEventMatchingKey getEventKey(ITmfEvent event) {
  99         IKernelAnalysisEventLayout layout = TRACE_LAYOUTS.get(event.getTrace());
 100         if (layout == null) {
 101             return null;
 102         }
 103
 104         TmfEventField content = (TmfEventField) event.getContent();
 105
 106         Long sequence = content.getFieldValue(Long.class, layout.fieldPathTcpSeq());
 107         Long ack = content.getFieldValue(Long.class, layout.fieldPathTcpAckSeq());
 108         Long flags = content.getFieldValue(Long.class, layout.fieldPathTcpFlags());
 109
 110         if (sequence == null || ack == null || flags == null) {
 111             return null;
 112         }
 113
 114         IEventMatchingKey key = new TcpEventKey(sequence, ack, flags);
 115         return key;
 116
 117     }
 118
 119 }